error parsing manifest

edit

Hello, I was following the tutorial "creating a ROS package by hand".

In my catkin_ws/src I created a folder mpc_wheelchair_pkg and I put a manifest there called "package.xml" and edited it like this

<package>

<name>mpc_wheelchair</name>
<version>0.0.0</version>
<description>blabla</description>
<mainteiner email="blabla@blabla">blabla</maintainer>
<license>BSD</license>

<buildtool_depend>catkin</buoldtool_depend>

<build_depend>rospy</build_depend>
<build_depend>std_msg</build_depend>

<run_depend>rospy</run_depend>
<run_depend>std_msgs</run_depend>

</package>

then I tried to use rospack as the tutorial suggested and this happened

viki@c3po:~$ rospack find mpc_wheelchair
    terminate called after throwing an instance of 'rospack::Exception'
      what():  error parsing manifest of package mpc_wheelchair_pkg at /home/viki/catkin_ws/src/mpc_wheelchair_pkg/package.xml
    Aborted

moreover if I now try "rospack find" with something else I always get the same exception

viki@c3po:~$ rospack find beginner_tutorials
terminate called after throwing an instance of 'rospack::Exception'
  what():  error parsing manifest of package mpc_wheelchair_pkg at /home/viki/catkin_ws/src/mpc_wheelchair_pkg/package.xml
Aborted

Does someone know what I should do? I use ROS indigo on a virtualboxed ubuntu.